1. Field of the Invention
The invention relates generally to photographic cameras, and particularly to improved film loading apparatus in a 35 mm camera. More specifically, the invention relates to loading apparatus in a 35 mm camera for correctly positioning a film leader for take-up in the camera whenever the leader is overextended (within a reasonable limit) from the film cartridge.
2. Description of the Prior Art
Typically, in 35 mm photography, the film is supplied in light-tight cartridges ready for loading into the camera. The cartridges are of simple construction including a rotatably supported spool on which the film is wound and a velvet or plush-lined, light-trapped slit from which protrudes a film leader of a predetermined length, e.g., 2.perspectiveto. in. To load the cartridge into the camera, the cartridge is positioned in a cartridge receiving chamber in the camera body with the leader pointing towards a film take-up chamber in the camera body. Then, enough of the film leader, e.g. another 1/4 in., is drawn out of the cartridge to reach a film take-up spool rotatably supported in the take-up chamber, and the leading end portion of the leader is placed in the take-up chamber for engagement with the take-up spool. The engagement is effected manually in some cameras, such as the Olympus OM-10, and automatically in other cameras, such as the Fujica DL-20. After the camera back is closed, the fogged section of the film is wound onto the take-up spool by rotating the spool to advance the film two or three frames.
Though the predetermined length of the film leader protruding from the cartridge varies from manufacturer to manufacturer, usually such length is not long enough for the leading end portion of the leader to be located beyond the take-up chamber when the cartridge is positioned in the cartridge receiving chamber. If the film leader is too long, however, and extends beyond the take-up chamber, for example, because the operator has pulled too much of the film from the cartridge or because the leader was too long originally, then the cartridge must be removed from the cartridge receiving chamber, and the film must be rewound into the cartridge by rotating the film spool located in the cartridge. This is not a good solution to the problem of an overextended leader, since the leading end portion of the leader may accidentally be rewound into the cartridge, in which case the leader cannot be retrieved without destroying the light trap on the cartridge.
Recently, the problem of an overextended leader has been addressed to some degree, as indicated in U.S. Pat. No. 4,459,000, granted July 10, 1984, by film cutting means in the camera. The cutting means is a scissors including one blade fixed on the camera body and the other blade having respective ends pivotally connected to the first blade and to the camera back. The blade connected to the camera back is actuated in response to closing movement of the camera back to cut off whatever portion of the leader extends beyond the take-up chamber, leaving a length of the leader that is suitable for automatic engagement with the take-up spool. Such cutting means is disadvantageous, however, in that it will dull with use until it can no longer cut the film leader.